January 14, 2015 [Issue 13981] New: std.algorithm: inconsistent handling of static arrays | ||||
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https://issues.dlang.org/show_bug.cgi?id=13981 Issue ID: 13981 Summary: std.algorithm: inconsistent handling of static arrays Product: D Version: D2 Hardware: x86_64 OS: Linux Status: NEW Severity: enhancement Priority: P1 Component: Phobos Assignee: nobody@puremagic.com Reporter: markus@oberhumer.com I'd guess this is a typical D newcomer issue as static arrays - are passed by value - are allocated on the stack (unless global) - are not real ranges because they lack popFront() Unfortunately I had to dig through various bugreports at issues.dlang.org before better understanding this issue, so I'd suggest adding a short comment to algorithms.d. In any case it's confusing that reduce() seems to work for static arrays while sum() does not. // dmd 2.066.1 import std.algorithm; void test_dynamic_array() { int[] arr1 = [1, 2, 3, 4, 5]; immutable int[] arr2 = [1, 2, 3, 4, 5]; filter!"a & 1"(arr1); // OK map!"a + 10"(arr1); // OK reduce!"a + b"(arr1); // OK sum(arr1); // OK filter!"a & 1"(arr2); // OK map!"a + 10"(arr2); // OK reduce!"a + b"(arr2); // OK sum(arr2); // OK } void test_static_array() { int[5] arr1 = [1, 2, 3, 4, 5]; static immutable int[5] arr2 = [1, 2, 3, 4, 5]; //filter!"a & 1"(&arr1); // Error: won't compile //map!"a + 10"(arr1); // Error: won't compile reduce!"a + b"(arr1); // OK ! //sum(arr1); // Error: won't compile //filter!"a & 1"(arr2); // Error: won't compile //map!"a + 10"(arr2); // Error: won't compile //reduce!"a + b"(arr2); // Error: won't compile ??? //sum(arr2); // Error: won't compile } -- |
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